394 



THE ARACHNOIDAE. 



^319. 



III. Male Arachnoidae. 



§ 319. 



From the few observations hitherto made upon the male organs of the 

 Acarina, it appears that they are formed after very different types. With 

 Trombidiiim, there are twenty red, testicular vesicles, attached by short 

 peduncles to the annular Vas deferens which opens between the posterior 

 legs. This last, before its termination, receives also two brown, long- 

 pedunculated vesicles, whose nature is yet unknown. <^' 



With Ixodes, the testicles consist of a group of four to five pairs of 

 longer or shorter follicles, which unite in the middle of the abdomen, and 

 send ofi" two small Vasa deferentia to the base of the chin-like process. 

 This last, together with the cheliceres, these animals introduce deep into 

 the vagina during copulation, while their two palpi, separated at a right 

 angle, are applied upon the thorax of the female.'-' With Gamasus, there 

 appear to be ,only two simple., isolated, testicular follicles, each having a 

 deferent canal. With many Acarina, there is a short penis situated at a 

 point corresponding to that of the vulva of the females, and sometimes 

 concealed within the body.''"' With other Acarina, the males are distin- 

 guishable from the females, by the larger size of their cheliceres, and some 

 of the legs which serve to retain the females during copulation.'^' 



With the Phalangidae, the testicles consist of numerous small caeca, all 

 united at one point into a long, flexuous deferent canal. This last is con- 

 tinuous into a Ductus ejaculatorius which traverses a muscular penis ; this 

 terminates with a hook-like gland, and its body is horny and surrounded by 

 a muscular sheath out of which it can be protruded under the thorax.'''^ 

 With many Opilionina, the posterior legs have remarkable spines and 

 excrescences which, undoubtedly, are used during copulation."^' 



With the Araneae, the testicles consist of two long, simple, interlaced 

 caeca, concealed between the hepatic lobes. "^' From them pass oflF two 



Taf. VII. fig. 18-20) ; Treviranus (Bau. d. 

 Avachn. p. 12, Taf. I. tig. 12), and Miiller (loc. cit. 

 J). 53 Taf. II. fig. 14^19). This last naturalist has 

 found, with the large African scorpions, eggs in the 

 lateral long, varicose and caecal appendages of the 

 ovaries. These appendages do not increase in size 

 except in proportion as the eggs are developed ; 

 while, with the small European scorpion, the eggs 

 produce only simple pyriform folds on the ova- 

 rian tubes. I have found sperm and very active 

 spermatic particles in the seminal receptacles of 

 living females of Scorpio europae.as. 



1 I have proved this complicated disposition of 

 the male organswith Trombidiiim holosericeum, 

 where it had been wholly misapprehended by 

 Treviranus (Verm. Schi'ift. I. p. 48, Taf. VI. fig. 

 35). 



^ This singular mode of coition had already been 

 oliserved by Degeer (loc. cit. p. 45, Taf. VI. fig. 

 6) with Ixodes ricinus, and subsequently by Ph. 

 fV. J. MiUler (Germar\s Magaz. d. Entomol. II. 

 1817, p. 281) ; but it remained wholly unobserved 

 by the other entomologists. It appears that the 

 male of Ixodes ricinus, which differs considerably 

 from the female, has been mistaken for a different 

 species and named Ixodes reduvius (Audouin, 

 loc. cit. XXV. p. 422, PI. XIV. fig. 4), or Ixodes 

 marginalis (flahn. Die Arachn. II. p. 63, fig. 

 153). The characters peculiar to this se.x are, a 



dorsal shield covering the whole body, palpi shorter, 

 and teeth less numerous upon the also shorter chin '^ 

 like process. 



3 The penis is sub-ventral with Bdella, sub-tho- 

 racic with Gamasus, and behind the genital orifice 

 with Oribates. With Jrrenurus, it is inserted 

 on a tuberosity of the abdomen, givmg the males a 

 very singular appearance (^Vuges, loc. cit. I. p. 

 155. PI. X. fig. 20). 



i With the males of certain species of Gamasus, 

 the two cheliceres are perforated, and the second 

 pair of legs is very stout and provided with spines 

 and excrescences. With Derma/eichus, it is the 

 third pair of these organs which is sometimes very 

 large and armed with robust nails. With Sarcop- 

 tes, the posterior legs are long and armed with 

 nails and discs, while with the females these same 

 legs are abortive. 



5 Treviranus, Verm. Schrift. I. p. 36, Taf. IV. 

 fig. 21, 22 ; and Tulk, loc. cit. p. 250, PI. IV. fig. 

 21-24. 



6 With Eusarcus, Gnnyleptes, &c. The very 

 large cheliceres of the Phalangidae are not used in 

 the act itself of copulation, but are employed to 

 fight with on these jealous occasions ; see LatreiUe, 

 Hist. Nat. d. Fourmis, p. 380. 



^ For the testicles of the Araneae, see Trevira- 

 nus, Bau d. Arachn. p. 37, Taf. IV. fig. 33, and 

 Brandt, Mediz. Zool. II. p. 89, Taf. XV. fig. 7. 



